

package com.hazelcast.client.impl.protocol.codec.builtin;

import com.hazelcast.client.impl.protocol.ClientMessage;

import java.util.function.BiConsumer;
import java.util.function.Function;

import static com.hazelcast.client.impl.protocol.ClientMessage.NULL_FRAME;

public final class CodecUtil {

    private CodecUtil() {
    }

    public static void fastForwardToEndFrame(ClientMessage.ForwardFrameIterator iterator) {
        // We are starting from 1 because of the BEGIN_FRAME we read
        // in the beginning of the decode method
        int numberOfExpectedEndFrames = 1;
        ClientMessage.Frame frame;
        while (numberOfExpectedEndFrames != 0) {
            frame = iterator.next();
            if (frame.isEndFrame()) {
                numberOfExpectedEndFrames--;
            } else
                if (frame.isBeginFrame()) {
                    numberOfExpectedEndFrames++;
                }
        }
    }

    public static <T> void encodeNullable(ClientMessage clientMessage, T value, BiConsumer<ClientMessage, T> encode) {
        if (value == null) {
            clientMessage.add(NULL_FRAME.copy());
        } else {
            encode.accept(clientMessage, value);
        }
    }

    public static <T> T decodeNullable(ClientMessage.ForwardFrameIterator iterator, Function<ClientMessage.ForwardFrameIterator, T> decode) {
        return nextFrameIsNullEndFrame(iterator) ? null : decode.apply(iterator);
    }

    public static boolean nextFrameIsDataStructureEndFrame(ClientMessage.ForwardFrameIterator iterator) {
        return iterator.peekNext().isEndFrame();
    }

    public static boolean nextFrameIsNullEndFrame(ClientMessage.ForwardFrameIterator iterator) {
        boolean isNull = iterator.peekNext().isNullFrame();
        if (isNull) {
            iterator.next();
        }
        return isNull;
    }
}
